猴头菌水溶性多糖的分离纯化与结构表征

从猴头菌子实体中分离得到一种新型的水溶性杂多糖HEPF2,分子量大小为1.66′104Da,该多糖由岩藻糖、半乳糖和葡萄糖以1.00:3.69:5.42比例构成,同时也含有微量的3-O-甲基鼠李糖。进一步利用傅立叶变换红外光谱法、糖组成分析、甲基化分析、部分酸水解法和核磁共振法等方法进行结构鉴定,检测结果表明,该杂多糖中包含1→4、1→6结合的葡萄糖和1→6结合的半乳糖残基,连接于主链的侧链残基,包括岩藻糖残基、少数的端基葡萄糖和半乳糖残基。核磁共振法检测结果还表明,1→4结合葡萄糖为β构型,(1→6)结合半乳糖、(1→2,6)结合半乳糖和端基葡萄糖均为α构型。     

紫球藻多糖化学结构解析

为明确紫球藻多糖的化学结构,本文采用化学分析和光谱分析方法对紫球藻多糖的一级糖链结构进行了分析。GC分析表明该多糖由木糖、葡萄糖和半乳糖组成,为一种杂多糖,其摩尔比为:2.96∶1.25∶3.06;红外光谱分析结果显示紫球藻多糖为硫酸化多糖,糖苷键类型为β构型;化学分析结果推断紫球藻多糖糖链连接方式以1→3为主,存在少量1→2,1→4,1→6键型,且半乳糖在支链或主链末端有较大量的存在,木糖和葡萄糖在主链或靠近主链区域有特定分布;NMR分析显示紫球藻多糖的硫酸酯基连在C-6上,且多糖的糖苷键为β型;GC-MS联机分析进一步确定紫球藻多糖为一种主要含有1→3糖苷键,并含有1→4,1→6糖苷键的杂多糖。综合上述分析,推断出紫球藻多糖的糖链主链的重复单元结构。     

两种灵芝孢子粉多糖的分离纯化和结构

本文采用水提醇沉法从灵芝孢子粉中提取其粗多糖,经Sepharose CL-6B凝胶柱层析分离得两种主要成分LBPI和LBPII,经高效液相色谱鉴定,均为高均一性成分,分子量分别为9.17×10 ⁴和1.86×10 ⁴;经酸水解、乙酰化和气相色谱分析,确定LBPI的单糖组成为甘露糖、半乳糖和葡萄糖,LBPII的单糖组成为鼠李糖、甘露糖、半乳糖和葡萄糖;通过高碘酸氧化、甲基化和GC-MS进行结构分析,确定LBPI中葡萄糖残基连接方式为1→、1→4,6和1→3,6连接,半乳糖残基为1→6连接,甘露糖残基为1→3,6连接,LBPII中鼠李糖残基连接方式为1→连接,葡萄糖残基为1→、1→4、1→6、1→4,6和1→3,6连接,半乳糖残基为1→6连接,甘露糖残基为1→2,3,6连接。综上,两种多糖LBPI和LBPII均为多分支的中型杂多糖,但两者的单糖组成和连接方式存在差异,这两种多糖成分均为首次报道,可望为灵芝孢子粉的成分、活性研究和资源开发提供理论依据。     

蛹虫草胞外多糖的研究 Ⅰ.半乳甘露聚糖(CM-I)的纯化和结构研究

从蛹虫草菌体培养液中提取水溶性粗多糖经分离纯化,得一种含有少量蛋白的半乳甘露聚糖CM-Ⅰ,分子量2.7×10~4,[α]_D~(19)=+54.7°。糖组成摩尔比,半乳糖:甘露糖=6∶5。经高碘酸氧化,Smith降解,部分酸水解,半乳糖苷酶解,~1H-NMR分析,完全甲基化与GC及GC-MS分析,证明:多糖CM-Ⅰ具有高度分枝结构,其以β-(1→2)连接的甘露糖为主干,枝链由较大量的β-(1→6)半乳糖和较大量的β-(1→2)呋喃半乳糖构成,分别连接在主干的0—4和0—6上。     

茶多糖TGC的结构表征

采用气相色谱-质谱联用技术(GC-MS)分析均一茶多糖TGC的单糖组成, 并与NMR, 圆二色谱、紫外扫描等其他分析方法结合, 对茶多糖TGC的一级结构及其在溶液中的构象加以探讨. 结果表明: 茶多糖TGC是由鼠李糖、阿拉伯糖、木糖、葡萄糖、甘露糖和半乳糖等6种单糖组成, 它在水溶液中应以有序的螺旋构象存在, 其一级结构为: 主链的骨架结构由鼠李糖、葡萄糖和半乳糖构成, 这3种单糖都有可能连接支链, 不接支链时其连接方式为β1→3, 支链主要由阿拉伯糖构成, 其连接方式可为β1→2, β1→3, β2→3三种, 木糖以β1→存在于主链和支链的末端.     

蛹虫草胞外多糖的研究I．半乳甘露聚糖(CM-I)的纯化和结构研究

从蛹虫草菌体培养液中提取水溶性粗多糖经分离纯化,得一种含有少量蛋白的半乳甘露聚糖CM-I,分子量2．7×10’,[a]19d=十54．7°。糖组成摩尔比,半乳糖： 甘露糖=6：5。经高碘酸氧化,Smith降解,部分酸水解,半乳糖苷酶解,1H-NMR分析,完全甲基化与GC及GC-MS分析,证明：多糖CM-I具有高度分枝结构,其以β-(1→2)连接的甘露糖为主干,枝链由较大量的β-(1→6)半乳糖和较大最的β-(1→2)呋喃半乳糖构成,分别连接在主干的0-4和0一6上。     

人参叶水溶性多糖——杂多糖P_N的纯化与结构初步确定

 从人参叶中提取的水溶性多糖经分离纯化得杂多糖P_N。P_N的分子量约为190万,单糖组成为阿拉伯糖、鼠李糖、木糖、半乳糖醛酸、半乳糖、葡萄糖及少量未知糖,单糖的摩尔比依次为8.1:0.8:1.0:1.6:12.5:4.1(未知糖除外)。经超离心分析,琼脂糖4B柱分析,玻璃纤维纸电泳和醋酸薄膜电泳鉴定等证明P_N为均一组份。经果胶酶降解,部分酸水解,高碘酸盐氧化,Smith降解,甲基化及其产物气相色谱(GLC)、气相色谱-质谱联用(GLC-MS)等结构分析表明P_N为多分支结构,分子的主链主要是由β-(1→3)连接的半乳糖组成,并在4—0和6—0上带有分支,平均每三个半乳糖有二个分支。     

两个赤芝子实体多糖的理化特性分析及结构鉴定

赤芝子实体多糖P32A分子量为506,322,P32B分子量为287,389,两种多糖均以己糖为主构成。P32A由鼠李糖、木糖、甘露糖和葡萄糖组成,四种单糖的摩尔比为：4．3：2．6：6．3：11．4;P32B亦由鼠李糖、木糖、甘露糖和葡萄糖组成,摩尔比为：1．2：1．0：2．1：9．2。该结果显示,P32A与P32B具有较类似的糖组成,且都以葡萄糖和甘露糖为主要单糖组分。根据^13C NMR和甲基化的结果分析知P32A可能含有l→4连接的葡萄糖构成的主链,非还原末端均由葡萄糖构成,此外P32A中还有l,4-连接的甘露糖和l,3—连接的鼠李糖。P32B可能以l→3连接形成主链,部分l,3-连接葡萄糖的6位有分支,该多糖也含有由葡萄糖构成的非还原末端,与P32A类似,P32B中还含有l,4-连接的甘露糖,不同的是不含l,3—连接的鼠李糖。     

虫草多糖的分离、纯化和初步药效活性研究

以虫草发酵菌丝体为原料提取虫草多糖并对多糖进行结构鉴定和初步药效活性研究。采用水提醇沉和离子交换纤维素进行分离得到两种虫草多糖,HPLC测定相对分子质量,紫外光谱、红外光谱、部分酸水解、甲基化分析和高效液相色谱等方法研究单糖组成及连接方式,四甲基偶氮唑盐微量酶反应比色法（MTT）检测虫草多糖的活性。经分离得到中性（CPSl）、酸性（CPS2）两种成分,相对分子质量分别为2．56×10^4,9．91×10^;单糖组成：CPSln,（葡萄糖）：n（甘露糖）：n（半乳糖）：n（阿拉伯糖）=46：36：18：l;CPS2／n,（葡萄糖）：n,（甘露糖）：n（半乳糖）：n（半乳糖酸）：n（木糖）：n（阿拉伯糖）：n（鼠李糖）=30：25：14：4：3：3：1。红外谱揭示均含-a-键。CPSl主链含（1→6）糖苷键的高度分支的葡甘露半乳聚糖,另有少量葡萄糖分支点在2,3,4位。CPS2主链含葡萄糖（Glc）、甘露糖（Man）、半乳糖（Gal）,分支点主要在3位,侧链含多种单糖。CPSl和CPS2都对顺铂（CDDP）损伤的vero细胞有一定保护作用。     

松杉灵芝发酵菌丝体中水溶多糖的分离纯化与结构的比较研究

松杉灵芝发酵菌丝体经热水提取,冻融分级及乙醇二次分级,分离纯化出GFb级份,电泳及凝胶柱层析示其为均一多糖,分子量为9.8万。小于子实体多糖相应级份。 GFb经红外光谱,气相色谱,气质联机,碳13核磁共振,高碘酸盐氧化,Smith降解,甲基化及部分酸水解分析,确定其基本结构中主链为1→6葡萄糖基和1→6半乳糖基构戍,二者之比为1∶1,分支点在0-3位上,分枝点率为50％,与子实体多糖GF_3相同,侧链由1→3葡萄糖基,1→4葡萄糖基,末端葡萄糖基及末端半乳糖基构成,分子中分枝率为55.6％,较子实体多糖GF_3分枝率略低,分枝链略短。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.